kernel/linux.git/drivers/vhost/vsock.c, branch linux-6.0.y

vhost/vsock: Fix error handling in vhost_vsock_init()

2023-01-12T11:00:33+00:00

[ Upstream commit 7a4efe182ca61fb3e5307e69b261c57cbf434cd4 ] A problem about modprobe vhost_vsock failed is triggered with the following log given: modprobe: ERROR: could not insert 'vhost_vsock': Device or resource busy The reason is that vhost_vsock_init() returns misc_register() directly without checking its return value, if misc_register() failed, it returns without calling vsock_core_unregister() on vhost_transport, resulting the vhost_vsock can never be installed later. A simple call graph is shown as below: vhost_vsock_init() vsock_core_register() # register vhost_transport misc_register() device_create_with_groups() device_create_groups_vargs() dev = kzalloc(...) # OOM happened # return without unregister vhost_transport Fix by calling vsock_core_unregister() when misc_register() returns error. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Yuan Can Message-Id: <20221108101705.45981-1-yuancan@huawei.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Acked-by: Jason Wang Signed-off-by: Sasha Levin

vhost/vsock: Use kvmalloc/kvfree for larger packets.

2022-10-21T10:38:19+00:00

[ Upstream commit 0e3f72931fc47bb81686020cc643cde5d9cd0bb8 ] When copying a large file over sftp over vsock, data size is usually 32kB, and kmalloc seems to fail to try to allocate 32 32kB regions. vhost-5837: page allocation failure: order:4, mode:0x24040c0 Call Trace: [] dump_stack+0x97/0xdb [] warn_alloc_failed+0x10f/0x138 [] ? __alloc_pages_direct_compact+0x38/0xc8 [] __alloc_pages_nodemask+0x84c/0x90d [] alloc_kmem_pages+0x17/0x19 [] kmalloc_order_trace+0x2b/0xdb [] __kmalloc+0x177/0x1f7 [] ? copy_from_iter+0x8d/0x31d [] vhost_vsock_handle_tx_kick+0x1fa/0x301 [vhost_vsock] [] vhost_worker+0xf7/0x157 [vhost] [] kthread+0xfd/0x105 [] ? vhost_dev_set_owner+0x22e/0x22e [vhost] [] ? flush_kthread_worker+0xf3/0xf3 [] ret_from_fork+0x4e/0x80 [] ? flush_kthread_worker+0xf3/0xf3 Work around by doing kvmalloc instead. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Junichi Uekawa Reviewed-by: Stefano Garzarella Acked-by: Michael S. Tsirkin Link: https://lore.kernel.org/r/20220928064538.667678-1-uekawa@chromium.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

vhost: rename vhost_work_dev_flush

2022-05-31T16:45:10+00:00

This patch renames vhost_work_dev_flush to just vhost_dev_flush to relfect that it flushes everything on the device and that drivers don't know/care that polls are based on vhost_works. Drivers just flush the entire device and polls, and works for vhost-scsi management TMFs and IO net virtqueues, etc all are flushed. Signed-off-by: Mike Christie Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Message-Id: <20220517180850.198915-9-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost_vsock: simplify vhost_vsock_flush()

2022-05-31T16:45:10+00:00

vhost_vsock_flush() calls vhost_work_dev_flush(vsock->vqs[i].poll.dev) before vhost_work_dev_flush(&vsock->dev). This seems pointless as vsock->vqs[i].poll.dev is the same as &vsock->dev and several flushes in a row doesn't do anything useful, one is just enough. Signed-off-by: Andrey Ryabinin Reviewed-by: Stefano Garzarella Signed-off-by: Mike Christie Acked-by: Jason Wang Message-Id: <20220517180850.198915-6-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: get rid of vhost_poll_flush() wrapper

2022-05-31T16:45:10+00:00

vhost_poll_flush() is a simple wrapper around vhost_work_dev_flush(). It gives wrong impression that we are doing some work over vhost_poll, while in fact it flushes vhost_poll->dev. It only complicate understanding of the code and leads to mistakes like flushing the same vhost_dev several times in a row. Just remove vhost_poll_flush() and call vhost_work_dev_flush() directly. Signed-off-by: Andrey Ryabinin [merge vhost_poll_flush removal from Stefano Garzarella] Signed-off-by: Mike Christie Reviewed-by: Chaitanya Kulkarni Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Message-Id: <20220517180850.198915-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vsock: each transport cycles only on its own sockets

2022-03-12T07:14:19+00:00

When iterating over sockets using vsock_for_each_connected_socket, make sure that a transport filters out sockets that don't belong to the transport. There actually was an issue caused by this; in a nested VM configuration, destroying the nested VM (which often involves the closing of /dev/vhost-vsock if there was h2g connections to the nested VM) kills not only the h2g connections, but also all existing g2h connections to the (outmost) host which are totally unrelated. Tested: Executed the following steps on Cuttlefish (Android running on a VM) [1]: (1) Enter into an `adb shell` session - to have a g2h connection inside the VM, (2) open and then close /dev/vhost-vsock by `exec 3< /dev/vhost-vsock && exec 3<&-`, (3) observe that the adb session is not reset. [1] https://android.googlesource.com/device/google/cuttlefish/ Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Reviewed-by: Stefano Garzarella Acked-by: Michael S. Tsirkin Signed-off-by: Jiyong Park Link: https://lore.kernel.org/r/20220311020017.1509316-1-jiyong@google.com Signed-off-by: Jakub Kicinski

vhost/vsock: don't check owner in vhost_vsock_stop() while releasing

2022-02-23T12:32:33+00:00

vhost_vsock_stop() calls vhost_dev_check_owner() to check the device ownership. It expects current->mm to be valid. vhost_vsock_stop() is also called by vhost_vsock_dev_release() when the user has not done close(), so when we are in do_exit(). In this case current->mm is invalid and we're releasing the device, so we should clean it anyway. Let's check the owner only when vhost_vsock_stop() is called by an ioctl. When invoked from release we can not fail so we don't check return code of vhost_vsock_stop(). We need to stop vsock even if it's not the owner. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Cc: stable@vger.kernel.org Reported-by: syzbot+1e3ea63db39f2b4440e0@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+3140b17cb44a7b174008@syzkaller.appspotmail.com Signed-off-by: Stefano Garzarella Acked-by: Jason Wang Signed-off-by: David S. Miller

vhost/vsock: cleanup removing `len` variable

2021-11-25T00:00:28+00:00

We can increment `total_len` directly and remove `len` since it is no longer used for vhost_add_used(). Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20211122163525.294024-3-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi

vhost/vsock: fix incorrect used length reported to the guest

2021-11-25T00:00:28+00:00

The "used length" reported by calling vhost_add_used() must be the number of bytes written by the device (using "in" buffers). In vhost_vsock_handle_tx_kick() the device only reads the guest buffers (they are all "out" buffers), without writing anything, so we must pass 0 as "used length" to comply virtio spec. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Cc: stable@vger.kernel.org Reported-by: Halil Pasic Suggested-by: Jason Wang Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20211122163525.294024-2-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Reviewed-by: Halil Pasic

vhost/vsock: support MSG_EOR bit processing

2021-09-05T20:23:09+00:00

'MSG_EOR' handling has similar logic as 'MSG_EOM' - if bit present in packet's header, reset it to 0. Then restore it back if packet processing wasn't completed. Instead of bool variable for each flag, bit mask variable was added: it has logical OR of 'MSG_EOR' and 'MSG_EOM' if needed, to restore flags, this variable is ORed with flags field of packet. Signed-off-by: Arseny Krasnov Link: https://lore.kernel.org/r/20210903123238.3273526-1-arseny.krasnov@kaspersky.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella